diff options
Diffstat (limited to 'kernel/fs/jfs/jfs_metapage.c')
| -rw-r--r-- | kernel/fs/jfs/jfs_metapage.c | 837 |
1 files changed, 837 insertions, 0 deletions
diff --git a/kernel/fs/jfs/jfs_metapage.c b/kernel/fs/jfs/jfs_metapage.c new file mode 100644 index 000000000..16a0922be --- /dev/null +++ b/kernel/fs/jfs/jfs_metapage.c @@ -0,0 +1,837 @@ +/* + * Copyright (C) International Business Machines Corp., 2000-2005 + * Portions Copyright (C) Christoph Hellwig, 2001-2002 + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See + * the GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include <linux/fs.h> +#include <linux/mm.h> +#include <linux/module.h> +#include <linux/bio.h> +#include <linux/slab.h> +#include <linux/init.h> +#include <linux/buffer_head.h> +#include <linux/mempool.h> +#include <linux/seq_file.h> +#include "jfs_incore.h" +#include "jfs_superblock.h" +#include "jfs_filsys.h" +#include "jfs_metapage.h" +#include "jfs_txnmgr.h" +#include "jfs_debug.h" + +#ifdef CONFIG_JFS_STATISTICS +static struct { + uint pagealloc; /* # of page allocations */ + uint pagefree; /* # of page frees */ + uint lockwait; /* # of sleeping lock_metapage() calls */ +} mpStat; +#endif + +#define metapage_locked(mp) test_bit(META_locked, &(mp)->flag) +#define trylock_metapage(mp) test_and_set_bit_lock(META_locked, &(mp)->flag) + +static inline void unlock_metapage(struct metapage *mp) +{ + clear_bit_unlock(META_locked, &mp->flag); + wake_up(&mp->wait); +} + +static inline void __lock_metapage(struct metapage *mp) +{ + DECLARE_WAITQUEUE(wait, current); + INCREMENT(mpStat.lockwait); + add_wait_queue_exclusive(&mp->wait, &wait); + do { + set_current_state(TASK_UNINTERRUPTIBLE); + if (metapage_locked(mp)) { + unlock_page(mp->page); + io_schedule(); + lock_page(mp->page); + } + } while (trylock_metapage(mp)); + __set_current_state(TASK_RUNNING); + remove_wait_queue(&mp->wait, &wait); +} + +/* + * Must have mp->page locked + */ +static inline void lock_metapage(struct metapage *mp) +{ + if (trylock_metapage(mp)) + __lock_metapage(mp); +} + +#define METAPOOL_MIN_PAGES 32 +static struct kmem_cache *metapage_cache; +static mempool_t *metapage_mempool; + +#define MPS_PER_PAGE (PAGE_CACHE_SIZE >> L2PSIZE) + +#if MPS_PER_PAGE > 1 + +struct meta_anchor { + int mp_count; + atomic_t io_count; + struct metapage *mp[MPS_PER_PAGE]; +}; +#define mp_anchor(page) ((struct meta_anchor *)page_private(page)) + +static inline struct metapage *page_to_mp(struct page *page, int offset) +{ + if (!PagePrivate(page)) + return NULL; + return mp_anchor(page)->mp[offset >> L2PSIZE]; +} + +static inline int insert_metapage(struct page *page, struct metapage *mp) +{ + struct meta_anchor *a; + int index; + int l2mp_blocks; /* log2 blocks per metapage */ + + if (PagePrivate(page)) + a = mp_anchor(page); + else { + a = kzalloc(sizeof(struct meta_anchor), GFP_NOFS); + if (!a) + return -ENOMEM; + set_page_private(page, (unsigned long)a); + SetPagePrivate(page); + kmap(page); + } + + if (mp) { + l2mp_blocks = L2PSIZE - page->mapping->host->i_blkbits; + index = (mp->index >> l2mp_blocks) & (MPS_PER_PAGE - 1); + a->mp_count++; + a->mp[index] = mp; + } + + return 0; +} + +static inline void remove_metapage(struct page *page, struct metapage *mp) +{ + struct meta_anchor *a = mp_anchor(page); + int l2mp_blocks = L2PSIZE - page->mapping->host->i_blkbits; + int index; + + index = (mp->index >> l2mp_blocks) & (MPS_PER_PAGE - 1); + + BUG_ON(a->mp[index] != mp); + + a->mp[index] = NULL; + if (--a->mp_count == 0) { + kfree(a); + set_page_private(page, 0); + ClearPagePrivate(page); + kunmap(page); + } +} + +static inline void inc_io(struct page *page) +{ + atomic_inc(&mp_anchor(page)->io_count); +} + +static inline void dec_io(struct page *page, void (*handler) (struct page *)) +{ + if (atomic_dec_and_test(&mp_anchor(page)->io_count)) + handler(page); +} + +#else +static inline struct metapage *page_to_mp(struct page *page, int offset) +{ + return PagePrivate(page) ? (struct metapage *)page_private(page) : NULL; +} + +static inline int insert_metapage(struct page *page, struct metapage *mp) +{ + if (mp) { + set_page_private(page, (unsigned long)mp); + SetPagePrivate(page); + kmap(page); + } + return 0; +} + +static inline void remove_metapage(struct page *page, struct metapage *mp) +{ + set_page_private(page, 0); + ClearPagePrivate(page); + kunmap(page); +} + +#define inc_io(page) do {} while(0) +#define dec_io(page, handler) handler(page) + +#endif + +static inline struct metapage *alloc_metapage(gfp_t gfp_mask) +{ + struct metapage *mp = mempool_alloc(metapage_mempool, gfp_mask); + + if (mp) { + mp->lid = 0; + mp->lsn = 0; + mp->data = NULL; + mp->clsn = 0; + mp->log = NULL; + init_waitqueue_head(&mp->wait); + } + return mp; +} + +static inline void free_metapage(struct metapage *mp) +{ + mempool_free(mp, metapage_mempool); +} + +int __init metapage_init(void) +{ + /* + * Allocate the metapage structures + */ + metapage_cache = kmem_cache_create("jfs_mp", sizeof(struct metapage), + 0, 0, NULL); + if (metapage_cache == NULL) + return -ENOMEM; + + metapage_mempool = mempool_create_slab_pool(METAPOOL_MIN_PAGES, + metapage_cache); + + if (metapage_mempool == NULL) { + kmem_cache_destroy(metapage_cache); + return -ENOMEM; + } + + return 0; +} + +void metapage_exit(void) +{ + mempool_destroy(metapage_mempool); + kmem_cache_destroy(metapage_cache); +} + +static inline void drop_metapage(struct page *page, struct metapage *mp) +{ + if (mp->count || mp->nohomeok || test_bit(META_dirty, &mp->flag) || + test_bit(META_io, &mp->flag)) + return; + remove_metapage(page, mp); + INCREMENT(mpStat.pagefree); + free_metapage(mp); +} + +/* + * Metapage address space operations + */ + +static sector_t metapage_get_blocks(struct inode *inode, sector_t lblock, + int *len) +{ + int rc = 0; + int xflag; + s64 xaddr; + sector_t file_blocks = (inode->i_size + inode->i_sb->s_blocksize - 1) >> + inode->i_blkbits; + + if (lblock >= file_blocks) + return 0; + if (lblock + *len > file_blocks) + *len = file_blocks - lblock; + + if (inode->i_ino) { + rc = xtLookup(inode, (s64)lblock, *len, &xflag, &xaddr, len, 0); + if ((rc == 0) && *len) + lblock = (sector_t)xaddr; + else + lblock = 0; + } /* else no mapping */ + + return lblock; +} + +static void last_read_complete(struct page *page) +{ + if (!PageError(page)) + SetPageUptodate(page); + unlock_page(page); +} + +static void metapage_read_end_io(struct bio *bio, int err) +{ + struct page *page = bio->bi_private; + + if (!test_bit(BIO_UPTODATE, &bio->bi_flags)) { + printk(KERN_ERR "metapage_read_end_io: I/O error\n"); + SetPageError(page); + } + + dec_io(page, last_read_complete); + bio_put(bio); +} + +static void remove_from_logsync(struct metapage *mp) +{ + struct jfs_log *log = mp->log; + unsigned long flags; +/* + * This can race. Recheck that log hasn't been set to null, and after + * acquiring logsync lock, recheck lsn + */ + if (!log) + return; + + LOGSYNC_LOCK(log, flags); + if (mp->lsn) { + mp->log = NULL; + mp->lsn = 0; + mp->clsn = 0; + log->count--; + list_del(&mp->synclist); + } + LOGSYNC_UNLOCK(log, flags); +} + +static void last_write_complete(struct page *page) +{ + struct metapage *mp; + unsigned int offset; + + for (offset = 0; offset < PAGE_CACHE_SIZE; offset += PSIZE) { + mp = page_to_mp(page, offset); + if (mp && test_bit(META_io, &mp->flag)) { + if (mp->lsn) + remove_from_logsync(mp); + clear_bit(META_io, &mp->flag); + } + /* + * I'd like to call drop_metapage here, but I don't think it's + * safe unless I have the page locked + */ + } + end_page_writeback(page); +} + +static void metapage_write_end_io(struct bio *bio, int err) +{ + struct page *page = bio->bi_private; + + BUG_ON(!PagePrivate(page)); + + if (! test_bit(BIO_UPTODATE, &bio->bi_flags)) { + printk(KERN_ERR "metapage_write_end_io: I/O error\n"); + SetPageError(page); + } + dec_io(page, last_write_complete); + bio_put(bio); +} + +static int metapage_writepage(struct page *page, struct writeback_control *wbc) +{ + struct bio *bio = NULL; + int block_offset; /* block offset of mp within page */ + struct inode *inode = page->mapping->host; + int blocks_per_mp = JFS_SBI(inode->i_sb)->nbperpage; + int len; + int xlen; + struct metapage *mp; + int redirty = 0; + sector_t lblock; + int nr_underway = 0; + sector_t pblock; + sector_t next_block = 0; + sector_t page_start; + unsigned long bio_bytes = 0; + unsigned long bio_offset = 0; + int offset; + int bad_blocks = 0; + + page_start = (sector_t)page->index << + (PAGE_CACHE_SHIFT - inode->i_blkbits); + BUG_ON(!PageLocked(page)); + BUG_ON(PageWriteback(page)); + set_page_writeback(page); + + for (offset = 0; offset < PAGE_CACHE_SIZE; offset += PSIZE) { + mp = page_to_mp(page, offset); + + if (!mp || !test_bit(META_dirty, &mp->flag)) + continue; + + if (mp->nohomeok && !test_bit(META_forcewrite, &mp->flag)) { + redirty = 1; + /* + * Make sure this page isn't blocked indefinitely. + * If the journal isn't undergoing I/O, push it + */ + if (mp->log && !(mp->log->cflag & logGC_PAGEOUT)) + jfs_flush_journal(mp->log, 0); + continue; + } + + clear_bit(META_dirty, &mp->flag); + set_bit(META_io, &mp->flag); + block_offset = offset >> inode->i_blkbits; + lblock = page_start + block_offset; + if (bio) { + if (xlen && lblock == next_block) { + /* Contiguous, in memory & on disk */ + len = min(xlen, blocks_per_mp); + xlen -= len; + bio_bytes += len << inode->i_blkbits; + continue; + } + /* Not contiguous */ + if (bio_add_page(bio, page, bio_bytes, bio_offset) < + bio_bytes) + goto add_failed; + /* + * Increment counter before submitting i/o to keep + * count from hitting zero before we're through + */ + inc_io(page); + if (!bio->bi_iter.bi_size) + goto dump_bio; + submit_bio(WRITE, bio); + nr_underway++; + bio = NULL; + } else + inc_io(page); + xlen = (PAGE_CACHE_SIZE - offset) >> inode->i_blkbits; + pblock = metapage_get_blocks(inode, lblock, &xlen); + if (!pblock) { + printk(KERN_ERR "JFS: metapage_get_blocks failed\n"); + /* + * We already called inc_io(), but can't cancel it + * with dec_io() until we're done with the page + */ + bad_blocks++; + continue; + } + len = min(xlen, (int)JFS_SBI(inode->i_sb)->nbperpage); + + bio = bio_alloc(GFP_NOFS, 1); + bio->bi_bdev = inode->i_sb->s_bdev; + bio->bi_iter.bi_sector = pblock << (inode->i_blkbits - 9); + bio->bi_end_io = metapage_write_end_io; + bio->bi_private = page; + + /* Don't call bio_add_page yet, we may add to this vec */ + bio_offset = offset; + bio_bytes = len << inode->i_blkbits; + + xlen -= len; + next_block = lblock + len; + } + if (bio) { + if (bio_add_page(bio, page, bio_bytes, bio_offset) < bio_bytes) + goto add_failed; + if (!bio->bi_iter.bi_size) + goto dump_bio; + + submit_bio(WRITE, bio); + nr_underway++; + } + if (redirty) + redirty_page_for_writepage(wbc, page); + + unlock_page(page); + + if (bad_blocks) + goto err_out; + + if (nr_underway == 0) + end_page_writeback(page); + + return 0; +add_failed: + /* We should never reach here, since we're only adding one vec */ + printk(KERN_ERR "JFS: bio_add_page failed unexpectedly\n"); + goto skip; +dump_bio: + print_hex_dump(KERN_ERR, "JFS: dump of bio: ", DUMP_PREFIX_ADDRESS, 16, + 4, bio, sizeof(*bio), 0); +skip: + bio_put(bio); + unlock_page(page); + dec_io(page, last_write_complete); +err_out: + while (bad_blocks--) + dec_io(page, last_write_complete); + return -EIO; +} + +static int metapage_readpage(struct file *fp, struct page *page) +{ + struct inode *inode = page->mapping->host; + struct bio *bio = NULL; + int block_offset; + int blocks_per_page = PAGE_CACHE_SIZE >> inode->i_blkbits; + sector_t page_start; /* address of page in fs blocks */ + sector_t pblock; + int xlen; + unsigned int len; + int offset; + + BUG_ON(!PageLocked(page)); + page_start = (sector_t)page->index << + (PAGE_CACHE_SHIFT - inode->i_blkbits); + + block_offset = 0; + while (block_offset < blocks_per_page) { + xlen = blocks_per_page - block_offset; + pblock = metapage_get_blocks(inode, page_start + block_offset, + &xlen); + if (pblock) { + if (!PagePrivate(page)) + insert_metapage(page, NULL); + inc_io(page); + if (bio) + submit_bio(READ, bio); + + bio = bio_alloc(GFP_NOFS, 1); + bio->bi_bdev = inode->i_sb->s_bdev; + bio->bi_iter.bi_sector = + pblock << (inode->i_blkbits - 9); + bio->bi_end_io = metapage_read_end_io; + bio->bi_private = page; + len = xlen << inode->i_blkbits; + offset = block_offset << inode->i_blkbits; + if (bio_add_page(bio, page, len, offset) < len) + goto add_failed; + block_offset += xlen; + } else + block_offset++; + } + if (bio) + submit_bio(READ, bio); + else + unlock_page(page); + + return 0; + +add_failed: + printk(KERN_ERR "JFS: bio_add_page failed unexpectedly\n"); + bio_put(bio); + dec_io(page, last_read_complete); + return -EIO; +} + +static int metapage_releasepage(struct page *page, gfp_t gfp_mask) +{ + struct metapage *mp; + int ret = 1; + int offset; + + for (offset = 0; offset < PAGE_CACHE_SIZE; offset += PSIZE) { + mp = page_to_mp(page, offset); + + if (!mp) + continue; + + jfs_info("metapage_releasepage: mp = 0x%p", mp); + if (mp->count || mp->nohomeok || + test_bit(META_dirty, &mp->flag)) { + jfs_info("count = %ld, nohomeok = %d", mp->count, + mp->nohomeok); + ret = 0; + continue; + } + if (mp->lsn) + remove_from_logsync(mp); + remove_metapage(page, mp); + INCREMENT(mpStat.pagefree); + free_metapage(mp); + } + return ret; +} + +static void metapage_invalidatepage(struct page *page, unsigned int offset, + unsigned int length) +{ + BUG_ON(offset || length < PAGE_CACHE_SIZE); + + BUG_ON(PageWriteback(page)); + + metapage_releasepage(page, 0); +} + +const struct address_space_operations jfs_metapage_aops = { + .readpage = metapage_readpage, + .writepage = metapage_writepage, + .releasepage = metapage_releasepage, + .invalidatepage = metapage_invalidatepage, + .set_page_dirty = __set_page_dirty_nobuffers, +}; + +struct metapage *__get_metapage(struct inode *inode, unsigned long lblock, + unsigned int size, int absolute, + unsigned long new) +{ + int l2BlocksPerPage; + int l2bsize; + struct address_space *mapping; + struct metapage *mp = NULL; + struct page *page; + unsigned long page_index; + unsigned long page_offset; + + jfs_info("__get_metapage: ino = %ld, lblock = 0x%lx, abs=%d", + inode->i_ino, lblock, absolute); + + l2bsize = inode->i_blkbits; + l2BlocksPerPage = PAGE_CACHE_SHIFT - l2bsize; + page_index = lblock >> l2BlocksPerPage; + page_offset = (lblock - (page_index << l2BlocksPerPage)) << l2bsize; + if ((page_offset + size) > PAGE_CACHE_SIZE) { + jfs_err("MetaData crosses page boundary!!"); + jfs_err("lblock = %lx, size = %d", lblock, size); + dump_stack(); + return NULL; + } + if (absolute) + mapping = JFS_SBI(inode->i_sb)->direct_inode->i_mapping; + else { + /* + * If an nfs client tries to read an inode that is larger + * than any existing inodes, we may try to read past the + * end of the inode map + */ + if ((lblock << inode->i_blkbits) >= inode->i_size) + return NULL; + mapping = inode->i_mapping; + } + + if (new && (PSIZE == PAGE_CACHE_SIZE)) { + page = grab_cache_page(mapping, page_index); + if (!page) { + jfs_err("grab_cache_page failed!"); + return NULL; + } + SetPageUptodate(page); + } else { + page = read_mapping_page(mapping, page_index, NULL); + if (IS_ERR(page) || !PageUptodate(page)) { + jfs_err("read_mapping_page failed!"); + return NULL; + } + lock_page(page); + } + + mp = page_to_mp(page, page_offset); + if (mp) { + if (mp->logical_size != size) { + jfs_error(inode->i_sb, + "get_mp->logical_size != size\n"); + jfs_err("logical_size = %d, size = %d", + mp->logical_size, size); + dump_stack(); + goto unlock; + } + mp->count++; + lock_metapage(mp); + if (test_bit(META_discard, &mp->flag)) { + if (!new) { + jfs_error(inode->i_sb, + "using a discarded metapage\n"); + discard_metapage(mp); + goto unlock; + } + clear_bit(META_discard, &mp->flag); + } + } else { + INCREMENT(mpStat.pagealloc); + mp = alloc_metapage(GFP_NOFS); + mp->page = page; + mp->flag = 0; + mp->xflag = COMMIT_PAGE; + mp->count = 1; + mp->nohomeok = 0; + mp->logical_size = size; + mp->data = page_address(page) + page_offset; + mp->index = lblock; + if (unlikely(insert_metapage(page, mp))) { + free_metapage(mp); + goto unlock; + } + lock_metapage(mp); + } + + if (new) { + jfs_info("zeroing mp = 0x%p", mp); + memset(mp->data, 0, PSIZE); + } + + unlock_page(page); + jfs_info("__get_metapage: returning = 0x%p data = 0x%p", mp, mp->data); + return mp; + +unlock: + unlock_page(page); + return NULL; +} + +void grab_metapage(struct metapage * mp) +{ + jfs_info("grab_metapage: mp = 0x%p", mp); + page_cache_get(mp->page); + lock_page(mp->page); + mp->count++; + lock_metapage(mp); + unlock_page(mp->page); +} + +void force_metapage(struct metapage *mp) +{ + struct page *page = mp->page; + jfs_info("force_metapage: mp = 0x%p", mp); + set_bit(META_forcewrite, &mp->flag); + clear_bit(META_sync, &mp->flag); + page_cache_get(page); + lock_page(page); + set_page_dirty(page); + write_one_page(page, 1); + clear_bit(META_forcewrite, &mp->flag); + page_cache_release(page); +} + +void hold_metapage(struct metapage *mp) +{ + lock_page(mp->page); +} + +void put_metapage(struct metapage *mp) +{ + if (mp->count || mp->nohomeok) { + /* Someone else will release this */ + unlock_page(mp->page); + return; + } + page_cache_get(mp->page); + mp->count++; + lock_metapage(mp); + unlock_page(mp->page); + release_metapage(mp); +} + +void release_metapage(struct metapage * mp) +{ + struct page *page = mp->page; + jfs_info("release_metapage: mp = 0x%p, flag = 0x%lx", mp, mp->flag); + + BUG_ON(!page); + + lock_page(page); + unlock_metapage(mp); + + assert(mp->count); + if (--mp->count || mp->nohomeok) { + unlock_page(page); + page_cache_release(page); + return; + } + + if (test_bit(META_dirty, &mp->flag)) { + set_page_dirty(page); + if (test_bit(META_sync, &mp->flag)) { + clear_bit(META_sync, &mp->flag); + write_one_page(page, 1); + lock_page(page); /* write_one_page unlocks the page */ + } + } else if (mp->lsn) /* discard_metapage doesn't remove it */ + remove_from_logsync(mp); + + /* Try to keep metapages from using up too much memory */ + drop_metapage(page, mp); + + unlock_page(page); + page_cache_release(page); +} + +void __invalidate_metapages(struct inode *ip, s64 addr, int len) +{ + sector_t lblock; + int l2BlocksPerPage = PAGE_CACHE_SHIFT - ip->i_blkbits; + int BlocksPerPage = 1 << l2BlocksPerPage; + /* All callers are interested in block device's mapping */ + struct address_space *mapping = + JFS_SBI(ip->i_sb)->direct_inode->i_mapping; + struct metapage *mp; + struct page *page; + unsigned int offset; + + /* + * Mark metapages to discard. They will eventually be + * released, but should not be written. + */ + for (lblock = addr & ~(BlocksPerPage - 1); lblock < addr + len; + lblock += BlocksPerPage) { + page = find_lock_page(mapping, lblock >> l2BlocksPerPage); + if (!page) + continue; + for (offset = 0; offset < PAGE_CACHE_SIZE; offset += PSIZE) { + mp = page_to_mp(page, offset); + if (!mp) + continue; + if (mp->index < addr) + continue; + if (mp->index >= addr + len) + break; + + clear_bit(META_dirty, &mp->flag); + set_bit(META_discard, &mp->flag); + if (mp->lsn) + remove_from_logsync(mp); + } + unlock_page(page); + page_cache_release(page); + } +} + +#ifdef CONFIG_JFS_STATISTICS +static int jfs_mpstat_proc_show(struct seq_file *m, void *v) +{ + seq_printf(m, + "JFS Metapage statistics\n" + "=======================\n" + "page allocations = %d\n" + "page frees = %d\n" + "lock waits = %d\n", + mpStat.pagealloc, + mpStat.pagefree, + mpStat.lockwait); + return 0; +} + +static int jfs_mpstat_proc_open(struct inode *inode, struct file *file) +{ + return single_open(file, jfs_mpstat_proc_show, NULL); +} + +const struct file_operations jfs_mpstat_proc_fops = { + .owner = THIS_MODULE, + .open = jfs_mpstat_proc_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; +#endif |